In such a cine camera the film must be transported intermittently, by the usual reciprocating-claw mechanism, past the exposure gate and at substantially constant speed past the recording head. An advantageous constant-speed feeder comprises a driven capstan and a pinch roller serving to clamp the film between itself and the capstan. Means for co-ordinating the two drives have been described in our prior applications referred to above and in our U.S. Pat. No. 4,003,643 granted on another application, Ser. No. 669,085, filed Mar. 22, 1976 as a continuation-in-part of abandoned application Ser. No. 460,136.
As further disclosed in our prior application and patents referred to, as well as in our copending application Ser. No. 669,110 filed Mar. 22, 1976 as another continuation-in-part of that abandoned application, now U.S. Pat. No. 4,066,345, the pinch roller and the capstan should be widely separated during the loading of the camera with a sound-film cassette in order to provide the necessary clearance for the insertion of an unsupported stretch of film therebetween; upon such insertion, and prior to the operation of a release button or trigger to start the film drive, the pinch roller and/or the capstan must be displaced to reduce their separation in order that a sound film can be engaged and transported thereby. Such displacement need not immediately clamp the film between the capstan and the pinch roller but may establish an intermediate or standby position from which the clamping position is reached upon operation of the trigger. In accordance with the disclosure of our U.S. patent last referred to, the relative displacement of the pinch roller and the capstan from a retracted position to at least a standby position is carried out with the aid of a manually operable external actuating member on the camera casing, that actuating member being independent of the trigger and comprising for example a bar manipulable by the fingers of a user or a door or lid of a cassette-receiving chamber.